Dozens of rusting barrels unearthed on former U.S. military land in Okinawa City have been identified as containing chemical precursors to defoliant Agent Orange, a toxic compound used widely in the Vietnam War and blamed for poisoning that has resulted in birth defects and other health problems.

Dug up more than five months ago, the 61 barrels contain three signature components of Agent Orange: the herbicides 2,4,5-T and 2,4-D, and the highly toxic TCDD dioxin, according to two independent teams of experts representing Okinawa City and the Okinawa Defense Bureau respectively.

It is the first time that all three ingredients have been identified on former U.S. military property on Okinawa.